Features of determining the time of evacuation of people from buildings in case of fire

Abstract

The object of the study is the safe evacuation time of people in case of fire from a typical secondary education institution. The problem was solved, which consisted in the inconsistency of the quantitative assessment of «pre-evacuation time» set out in DSTU 8828:2019, which is regulated by the requirements of DBN B.2.5-56:2014, with today’s conditions, when determining the safe time of evacuation from buildings and structures. Thanks to the obtained results, features were revealed that fully determine the dependence of the relationship between the pre-evacuation time and warning systems on the example of a typical secondary education institution. The evacuation time was determined according to DSTU 8828:2019, taking into account the requirements of DBN B.2.5-56:2014. The total evacuation time from the building was 687 s. The time of blocking evacuation routes and evacuation exits by dangerous fire factors is determined. The results of the recorded temperature did not exceed 46 оC, the value of oxygen was not recorded lower than ≥0,226 kg/m3, the density of carbon monoxide was not more than ≤1,16•10-3 kg/m3 during the total evacuation time, which meets the requirements of fire safety. The results of the recorded visibility exceed the maximum permissible values. Thus, the path to evacuation exit № 1 using stairwell № 1 takes place through door № 7. Movement through this door lasts for 531 s, therefore, now when the last person passes through stairwell and door № 7, the visibility is already ≤6 m. Therefore, evacuation through stairwell № 1 is dangerous. In addition, the last person passes through the door of the evacuation exit № 1 for 550 s, where the visibility value is ≤9 m, which is also an excess of the maximum permissible values, according to the requirements.